With the huge increase in numbers of tall office buildings, condominiums, and apartment buildings, and with the large number of fires that have occured in these buildings in recent years, there is a great need for a reliable, simple and usable fire escape ladder which may be kept by persons for portable use.
While ordinary rope ladders which hook over a window sill are well known, they suffer from many problems. Most of them are too heavy and cumbersome for use. They can be made only of a given length so that only a certain distance can be traveled on the ladder. They are then fixed on the window ledge where they were set, and cannot be removed from the ledge. Certain devices have been proposed for hooks that are removable from the ledge, but these require complex mechanical devices.
Quite often in fire situations today, it is more beneficial for the party to escape by going upward to the roof than it is to go down. No fire escape ladder, known today, allows that ability.